In the sentence "Yo podía verlo todos los días, pero ahora ya no vive aquí", the verb podía is in the imperfect tense because it describes a habitual or ongoing ability in the past. In other words, podía here implies "I was able to (repeatedly)" or "I used to be able to," reflecting a continuous or repeated condition rather than a specific moment.

Here’s how this works:

Imperfect (Podía): Used to express a habitual or ongoing ability in the past.

Example: Yo podía verlo todos los días.
Translation: "I could (used to be able to) see him every day."
Indicative Conditional (Podría): Used to express a hypothetical ability or possibility, often tied to "I could" or "I would be able to" in English.

Example: Yo podría verlo si viviera aquí.
Translation: "I could see him if he lived here."
In the context of your example, podía is appropriate because it refers to an ability that was possible regularly or habitually in the past. The conditional (podría) would not fit here because it suggests a hypothetical or conditional situation, which is not the case in this sentence.

I hope this clarifies the difference!